Seminar 6th December 2001, at Department of Population Ecology
"Social parasitism and sympatric speciation"
by
Riita Savolainen
Department of Ecology and Systematics, University of Helsinki, Finland
Abstract:
Several social Hymenopteran families include completely or nearly workerless social
parasites, inquilines, which exploit the host workforce to maximize their own production of
sexual offspring. Emery’s rule suggests that social parasites are close (loose form of the
rule) or closest (strict form) relatives to their host species. If closest, they have evolved
from their most recent common ancestor, which would imply multiple, independent origins
of social parasitism even within a single genus, probably through sympatric speciation.
Phylogeny-based studies on several Hymenopteran taxa have tested and rejected the
strict Emery’s rule, though the evidence of all social parasites being close relatives to their
hosts is convincing. Here I test the strict Emery’s rule and the plausibility of sympatric
speciation using Bayesian phylogenetic inference to reconstruct the phylogenetic
relationships of three inquiline–host pairs of Myrmica ant species. The data includes parts
of three mitochondrial genes, in total 2772 bp. I show that these social parasites are
polyphyletic and that such polyphyly, not earlier reported in social insects, strongly
suggests multiple, independent origin of the parasite species through sympatric speciation.
The social biology and ecology of Myrmica support this concept.
Place:
Thursday 6th November, at 15:00
Department of Population Ecology
Building 12, Kollokvierum 1, 1st floor
Universitetsparken 15
2100 Kbh.Ø.